Many nucleic acid sequences have been used to diagnose and monitor disease, detect risk and decide which therapies will work best for individual patient. For example, the presence of nucleic acid sequences associated with infectious organisms may indicate an infection by the organism. The presence of an altered nucleic acid sequence in a patient sample may indicate activation or inactivation of a pathway related to a disease or disorders.
Detection of clinically related nucleic acid sequences in a sample generally involves isolating nucleic acid from the sample and amplification of specific nucleic acid sequences followed by detection of the amplified products. However, complexities of the multi-step process of isolating nucleic acid limit the processing flexibility and reduce the repeatability. For example, DNA and RNA have different chemical properties and stability, whose preparation requires different processing conditions. Further, samples from different source organism may require different steps to isolate nucleic acids. For example, isolating DNA from bacteria may use harsher conditions (e.g., higher temperature, higher concentration of detergent, etc.) than releasing DNA from relatively labile mammalian cells. Therefore, there is a need for an analytical system providing flexible and adjustable operating capabilities to meet the diverse demands of clinical diagnostics. Moreover, although amplification increases the sensitivity of the detection assay by providing sufficient copies of the specific nucleic acid sequences, it may risk erroneous results born of contamination. Therefore, there is also a need for an analytical system requiring minimal user participation to reduce contamination.